Document
STV6120
8PSK/QPSK low-power 3.3-V dual wide-band satellite tuner IC
Data brief
Features
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Low power consumption Compatible with 5- and 3.3-V I2C bus
Four VLNA inputs On-chip 4:2 matrix Input frequency range 250 MHz to 2150 MHz Two independently programmable tuners RF to baseband direct conversion Single 3.3-V DC supply Fractional N synthesizers Extremely low phase noise, compliant with DVB-S2 requirements Flexible crystal frequency output to drive the demodulator IC Continuously variable gain: 0 to 65 dB Additional and programmable gain on baseband amplifier: 0 to 16 dB Programmable 5- to 36-MHz cut-off frequency (Butterworth 5th-order baseband filters)
Applications
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Direct broadcasting satellite (DBS) QPSK/8PSK demodulation Set-top box
Package
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VFQFPN-56 8 x 8 x 1 mm3 with exposed pad down (EPD) for heat dissipation ECOPACK®, environmentally friendly package
Description
The STV6120 satellite tuner is a quad-input dual direct-conversion (zero-IF) wideband satellite tuner intended for digital set-top boxes and similar applications.
RFAin RFBin VLNA + Matrix 4:2
PLL1 +dividers1
DC offset compensation 1 QP1 QN1 IN1 IP1 QP2 QN2 IN2 IP2
RFCin
RFDin
AGC1 AGC2 XTAL_IN XTAL_INN XTAL_OUT XTAL Amplifier
PLL2 + dividers2
DC offset compensation 2 SCL I2C Bus Interface SDA
November 2011
Doc ID 022527 Rev 1
1/4
www.st.com 4
For further information contact your local STMicroelectronics sales office.
http://www.Datasheet4U.com
Introduction
STV6120
1 Intr
oduction
The STV6120 dual tuner has four identical wideband RF inputs. The switch matrix 4:2 allows the selection of the appropriate RF input for each down-conversion path. After the matrix, there is a high-frequency low-pass filter followed by two down mixers. Each mixer, which down-converts the signal to baseband, is followed by a low-pass filter and amplifying stages. The baseband gain can be varied by programming a register through the I2C bus. The local oscillator signals are provided by two integrated fractional-N PLLs. Each PLL contains an on-chip voltage controlled oscillator, which meets stringent phase noise requirements. The PLL loop filters are partially integrated. The local oscillator frequencies are programmable between 250 and 2150 MHz. The comparison frequency for the phase-frequency detector is generated by dividing the crystal oscillator reference frequency. The crystal frequency will be in the range 16 MHz to 30 MHz depending on the application. The design of the STV6120 has been carefully implemented to avoid the problems associated with having two tuners integrated on a single chip.
Features
Quad tuner inputs 4:2 switch matrix
Benefits
Fits universal quad and Quattro LNB requirements or if fewer inputs are used, very high isolation Low-cost, high-performance BoM integration allowing flexibility between legacy systems and SCR (unicable) systems Wide choice of crystal frequencies with robust clock buffer to drive second tuners and de.